Chapter 2 287
Performance Verification Tests
32. Spurious Responses: Agilent E4404B, E4405B, E4407B, and E4408B
Measuring 1.55 GHz Second Harmonic Distortion
1. Replace the 1.GHz low pass filter with the two 1.8 GHz low pass
filters as shown in Figure 2-50. Two filters are necessary to reduce
the second harmonics from the source to less than –100 dBc.
2. On the synthesized sweeper, press the following:
CW, 1.55 GHz
POWER LEVEL, 6dBm
3. Enter the power sensor 2 GHz calibration factor into the power
meter.
4. On the analyzer, press the following:
FREQUENCY, 1.55 GHz
AMPLITUDE, Ref Level, 0 dBm
AMPLITUDE, Attenuation, 10 dB (Man)
Peak Search (or Search).
5. Adjust the synthesized sweeper power level until the power meter
reading is 0 dBm ±0.1 dB.
6. On the analyzer, press the following:
Peak Search (or Search)
Marker, Delta
FREQUENCY, Center Freq, 3.1 GHz
7. See Figure 2-50. Remove the 1.8 GHz low pass filters and connect
the synthesized sweeper output directly to the power splitter input.
8. On the analyzer, press the following:
Peak Search (or Search)
AMPLITUDE
Presel Center
9. Reinstall the filters between the synthesized sweeper and the power
splitter.
10.On the analyzer, press the following:
AMPLITUDE, Ref Level, –40 dBm
BW/Avg, Video BW, 30 Hz (Man)
11.On the analyzer, press BW/Avg, Average, 10 Hz. Wait until “VAvg 10”
is displayed along the left side of the display.
12.On the analyzer, press Peak Search (or Search). The marker delta (∆
Mkr1) amplitude reading is the second harmonic suppression.